Mechanical pencil



Dec. l1, 1928.

, C. R. KEERAN MECHANICAL PENCIL Filed 0011. 5, 1925 Patented Dec. 11,1928.

UNITED STATES PATENT OFFICE.

CHARLES R. KEERAN, 0F EVANSTON, ILLINOIS, ASSIG'NOR TO KEERAN PRODUCTSCOMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

MECHANICAL PENCIL.

Application led October '3, 192.5. Serial No. 60,230.

My invention relates to mechanical pencils, and particularly to animprovement in the construction shown in my copending application S. N.49,569, tiled Aug. 11, 1925 of which this application is a continuationin art.

p One of the objects of my invention is to simplify the construction ofpencils of the class described, and to improve 'the inter nalarrangement of parts so as to facilitate assembling and thereby toreduce manufacturing costs.

The invention will be more readily understood by reference to theaccompanying drawing, in which;

Fig. 1 is a longitudinal sectional view through a pencil constructed inaccordance with my invention;

Fig. 2. is a similar view through a slightly modified form of theinvention;

Fig. 3 is a fragmentary view through a still further modification;

Fig. 41 is a fragmentary view showing the arrangement of parts with thetip and attached spiral tube removed and with the lead advancing plungerin its extreme outward position;

Fig. 5 is a sectional view on the line 5--5 of Fig. 1; l

. Fig. 6 is a sectional view on the line 6-6 of Fig. 1.

Fig. 7 is a sectional view on the line 7 7 of Fig. 2.

In the drawings, and referring vparticularly to Fig. 1, it will be seenthat the device comprises av long inner tube, 10, that constitutes thebody, corresponding to the barrel of an ordinary all-metal pencil.Surrounding the tube, 10, is a decorative barrel, 11, that may becomposed of Celluloid or similar material.

The' upper end of the inner tube is partly closed by an aperture disc,12, held in position by spinning over'1 the end, 13, of the tube. Thearcuate apertures, 14 in the disc, provide for the insertion and removalof reserved leads, indicated at 15, in Fig. 5.

The forward end of the tube, 10, is tapered inwardly as at 16, for apurpose hereafter described. Mounted within the tube and firmly held byfrictional engagement are two plates, 17 17 X of similarpform in reversearrangement and mounted in face to face .relation within andlongitudinally of the inner tube, 10. The assembly of the divisionplates provides an internal tube, 18, and a parallel guideway, 19, thesides of `which are undercut and which is in comparts is easilyaccomplished. By making the width of the plates, 17, 17 slightly greaterthan the cross sectional diameter of the tube, 10, the parts may besprung suficiently to force them into their proper position vand theywill be held therein by the resiliency of the metal.

The undercut guideway,p19,-provides for the reception and holding of thehead, 20, of the lead advancing plunger, 21, the head being connected tothe plunger through a lateral arm, 22. The arm, 22, engages with thespiral slot, 23, in a tube, 24, fixed by .means of solder, 25, to thetip, 26. It will be noted that the head has converging side walls, thecontour ofthe head in crosssection conforming to the cross section ofthe guideway, 19. Thus-the head is firmly held against lateral movementwhile permitted from longitudinal movement.

The lower end of the tube, 10, is provided with a sleeve or bushing,10', of hard rubber or similar material, provided for several purposes.First; to act as a stop for holding the barrel, 11, in place againstdownward movement; second, to provide for additional material to fillthe space that would otherwise result in a jog at the junction of thebarrel and the tip, and third; to provide for a better surface for therotative engagement o`f the tip with the pencil body. The cylindricalportion, 27, of the tip lits over the bushing, 10', with capacity forrotation and for removal when a renewal lead is to beinserted. f

The plates of the division wall, 17, 17 are tapered oil at their lowerends on both sides, to fit within the tapered portion, 16, of the innertube, thus extending the guidway, 19, into the tapered portion of thetube. This is for the purpose of permitting the plunger head to travelforwardly into the cont acted portion of the tube, as shown in Frig. 4,where it is held rmly against displacement laterally and'prevented fromescape at the lower end of the pencil. Thus upon removal of the tip andattached spiral, the plunger will travel to the limit of its downwardmovement and upon rotation of the tip the spiral may be disengaged fromthe plunger.

Thus there are but two parts for the userv 10, is ex anded slightly at10, and a groove,

29", is ormed therein to receive the head, 29, of a clip, 29. A ferruleor sleeve, 28,'is mounted over the expanded portion and the head of theclip and is relatively permanently secured in position. A split eraserholder, 30, is mounted Within the sleeve and acts as a closure for thereserve lead chambers. 'lhe eraser holder is constructed to receive arelatively long eraser, 31 and `to support the same in differentpositions of outward adjustment. A decorative cap, 32,- may surmount theerrule and cover the cap. It will be noted that the expanded portion of`the inner tube and the sleeve mounted thereon constitute a stop orabutment for the upper end of the barrel, 11.

y In the construction of Fi 2, the described` parts are identical exceptt at the operative length of the spiral tube is lessened. A bead, 33, isvrolled in the inner tube, 10, and this serves as a stop for a disc, 34,which constitutes the bottom of the reserve lead chamber. The sectionalwall construction heretofore described may be employed if desired, inwhich case the ends .of the plates are shaped to provide extensions,17", which tit within a recess, 34, in the disc and serve to center theplates. The chamber at the upper end of the body provides for a lar estock of short reserve leads although t e total length of'reserve leadsis no greater than that provided for in the constructionv a1- readydescribed.

vIn the construction shown in Fig. 3, there is no change except that theinner tube, 10",

is not provided with a decorative barrel,

the lower end of the tube bein -reduced to provide a shoulder or stopfor t e tip. The pencil need be varied in no other particular so far asthe operative parts are concerned.

The operation will be apparent. In each of the described forms, relativerotation of the tip and body will effect an advance of the lead, 15a.When the lead is exhausted, a-

I claim 1. A pencil comprising in combination a tube extending from endto end, the side walls of which tube are imperforate, means providing aninternal coaxial tube and an undercut guideway in communication withsaid coaxial tube, a plunger havin a head adapted for movement and connein. said guideway, a tip and an attached spiral, said spiral beingadapted Jto enter said coaxial tube and to actuate said plunger.

2. A pencil, comprising in combination a tube, extending from end toend, the side walls of which tube are imperforate, means providing aninternal coaxial tube and an undercut gui'deway, in communication withsaid coaxial tube, a plunger having a head ada ted for movement andconlined in said gui eway, a .tip and an attached spiral, said spiralbeing adapted to enter said coaxial tube and to actuate said plunger,and means preventing the withdrawal of said plunger head from the lowerend'of said guideway.

3. In apencil, the combination of a tube comprising a barrel, a tip andan attached spiral, means in said tube providing a guideway, the sidesof which are undercut, a plunger having a head adapted to be retained insaid guideway against movement in a lateral direction, and meansassociated with said guideway preventing the escape of the plunger fromthe lower end of the pencil.

4. In a pencil, the combination of a tubular body, a tip and an attachedspiral removably mounted on the lower end of said body, a division wallin said body providing an internal coaxial tube and a parallel guide-Way and a plunger having a head cooperating with said guideway.

' 5. A pencil, comprislng in combination a tubular body, a removable tipand a spiral attached to said tip, a pair of division lates,frictionally h eld within the said bo y and `jointly providing a coaxialtube and a com- .municating ideway, and a plunger having a head slida lymounted insaid ideway.

6. A pencil, comprising in com ination a tubular body, la removable tiand a spiral attached to said tip, a air of ivsion plates,frictionally'held within the saidA .body and jointly providing-a coaxialtube and acommunicating undercut ideway, and a plunger having a head sliably mounted in said guideway.

( 7. A pencil, comprising in combination a tubular body, a removable tipand a spiral attached to said tip, a air of division lates, frictionallyheld withm the said bo y and jointly providing a coaxial tube and acommunicating undercut guideway,a plunger having a head slidably mountedin said guideway, and means preventing the withdrawal of the plungerfrom the lower end of the pencil.

8. In a pencil, the combination of a tubular body having a contractedlower end, a tip removably mounted on the lower end of the body andhaving a spiral attached thereto, means providing a coaxial-tube in saidbody and an undercut guideway in communication with said coaxial tube, aplunger having a head slidable in said .guideway, and prevented fromlateral movement by reason of the undercut Walls of said guideway, the

tapered lower end of vsaid body serving to prevent the withdrawal of theplunger from the lower end of the pencil.

9. In a pencil, the combination of a metallic body portion, a tipremovably mounted on the lower end thereofv lead advancing means adaptedto be actuated by the rotation of said tip and a decorative shellsurrounding said body, the lower ex-I tremity of said shell constitutinga shoulder or abutment for the upper end of thetip.

10. In a pencil, the combination of a tijbular body, a tip removably androtatably mounted on the lower end of the body, a spiral attached to thetip, a divisional wall providing an internal tube and a guideway incommunication therewith, a plunger having a head slidablel in saidguideway, the space surrounding said wall constituting a pair of reservelead chambers.

11. In a pencil the combination of a body having an axial opening, atube therein having a longitudinal guide slot, the sides of the sletconverging inwardly so that the inner portion of the slot which isnearer the axis of the tube is narrower than the outer portion, a tipwith a tube fixed therein, said tube having` a spiral slot, a plungerhaving a lateral projection adapted to extend through the slot in thetube, and a head fixed to said projection, said head `having a -part ofgreater width than the width of the narrower portion of thelongitudinalguide slot in said first mentioned tube and adapted to slide in saidslot.

tube having a spiral-slot, a plunger' having' a lateral projectionadapted to extend through the slot in the tube, a head fixed to saidprojection, said head having a part of greater width than the width ofthe narrower portion of the longitudinal guide slot in said firstmentioned tube and adapted to slide in said slot, and means preventingthe withdrawal of the plunger from the forward end of said firstmentioned tube.

13. In a pencil the combination of a body having an axial opening, atube therein having a longitudinal guide slot, a tip removably fitted intheI forward end of the body, a helically coiled member fixed at one endto the tip and acting as a lead tube, the coils of the helix beingspaced to form a slot which is open at the other end of said member, aplunger in said lead tube, said plunger having a lateral portionextending through the space between adjacent turns of the helix, and ahead fixed to the projection and operating in the guide slot of thefirst mentioned tube, the forward end of said guide slot being formed toact as a stop for said plunger head, the relative dimensions of the headand the guide slot being such that tie head cannot pass laterallythrough the s ot. r

14. In a pencil the combination of a barrel having a central opening, atube frictionally held in the opening, said tube having a longitudinalguide slot provided with inwardly inclined sides, a tip and attachedlead tube having a helical slot, a plunger in said lead tube and aplunger head constructed to engage and slide in said guide slot, thesides of the head being inclined corresponding to the incline of thesides of the guide slot, whereby the plunger is permitted to slidelongitudinally but is confined against removal except with said guideslot tube.

15. In a pencil the combination of a body having an axial bore with alongitudinal guide slot, a tip at the writing end of the pencilrotatably engaged with the body and having a spirally slotted tuberemovably telescoped within the bore of the body, a plunger in said borehaving a lateral projection engaging the guide slot, the upper end ofthe spiral slot being open for engaging and disengaging said projection.

16. In the combination defined in claim 15, the lower end of the guideslot being formed to arrest the projection and prevent withdrawal of theplunger from the lower end of the bore. 4

In testimony whereof I have affixed my signature.

CHARLES R.. KEERAN.

